The present invention relates to a method and a system to count moving articles and, more particularly, to a method and a system for counting irregularly shaped articles being moved into a machine that performs printing, slotting and cutting operations on such articles to form finished boxes which are also counted as they are being moved out of the machine.
Methods and systems for counting moving articles are known and are described in U.S. Pat. Nos. 4,166,246 (Matt); 4,237,378 (Jones); 4,504,916 (Oka) 4,665,392 (Koontz) and 4,881,248 (Korechika). U.S. Pat. No. 4,166,246 discloses a counting system used in the packaging industry.
In the manufacturing process of packaging boxes, it is common to use an initial blank that has irregularly shaped portions such as flap regions as well as irregularly occurring spaced cutouts in the blanks. Machines using such blanks commonly have a counter/ejector assembly whose operation is dependent on accurate counting. For such assemblies, blank counting is commonly accomplished by a retro-reflective photocell that senses the presence of blanks. Accurate counting by such sensing is made difficult by the presence of dark, black or brown, printed images or cutouts in the blank that may be present in the optical path of the photocell. These images and cutouts cause the photocell to change states several times before the actual blank end, and thus create multiple counts for each blank which, in turn, may be misinterpreted by the counting means.
To combat this misinterpretation, the photocell may be physically moved to an area of the blank, which moves past the photocell, that does not have printing or cutouts. For certain type blanks used in the formation of certain style boxes, it is not always possible to provide such an area. Further, moving the photocell is time consuming and has attendant production losses that may be encountered each time different style boxes are to be formed.
It is an object of the present invention to provide a system that does not suffer the drawbacks of the prior art devices and which accurately counts moving articles, such as irregularly shaped blanks, and different style formed boxes.
It is a further object of the present invention to provide a method which accurately counts the articles in spite of the presence of various dark images as well as cutouts.
Still further, it is an object of the present invention to provide a machine having a counter/ejector assembly that accurately counts both initial irregularly shaped blanks and different style boxes that are formed by the machine.